1. Field of the Invention
This invention relates to the field of devices made for operation of touch responsive user interfaces. More specifically, the invention comprises a stylus modified for attachment to a user's thumb or finger so as to operate a device using a touch-screen or small buttons.
2. Description of the Related Art
Personal Digital Assistants (PDA's) including electronic organizers, palmtops, and other hand-held devices are in wide use today. PDA's typically have a touch-screen and/or small buttons allowing data entry and selections. Generally a user would operate the touch-screen and small buttons with the provided stylus (in the shape of a small pen) or the user's finger.
A small pen-shaped stylus is utilized in much the same way as a pen. The stylus allows the user to make contact with the touch-screen commands or small buttons. However, the small size of the stylus and screen makes these operations awkward. Additionally, the user must hold the device in one hand and operate the stylus with the other hand, leaving no hand free. Using a fingertip in place of the stylus is also difficult, as the tip of a finger is broad compared to the small touch-screen command buttons. Using a stylus instead of a finger is preferable, since the transfer of natural oils from a user's finger onto the touch-screen shortens the life of the touch-screen.
The iPhone, created and sold by Apple, Inc., of Cupertino, Calif., is becoming a popular replacement for traditional PDA devices. Although some aspects of the iPhone's functionality are similar to traditional PDAs, there are some significant differences. One of these differences is the iPhone's multi-touch-screen technology. The iPhone touch-screen, unlike current PDA touch-screen technology, utilizes a layer of capacitive material to sense contact. If the user touches the capacitive material the amount of charge at the contact point changes. The capacitive touch screen monitors that change in the electrical current to determine the point of user contact on the screen. Like a traditional PDA, the individual touch-screen commands are cumbersome to contact by way of the user's finger, especially when trying to compose an e-mail on the virtual keyboard. However, unlike a traditional PDA, a prior art stylus will not interact with the capacitive touch-screen, due to the mechanical and electrical properties of the stylus.
A stylus allowing one-handed operation of a conventional touch-screen device and operational interaction with a capacitive touch-screen device would be desirable. Unfortunately, these dual requirements mean that the stylus, which spans the distance between the screen and the user's thumb or finger, will need to have different characteristics for the different applications. The present invention achieves this objective by using appropriate materials for the stylus, as well as appropriate geometry.